Full Grain Premium 2.2mm Cowhide Waterproof Leather Oil & Acid Resistant Outsole w/Non-Skid & Non-Marking Tread Back Calf Lacing Detail, Welt Construction Side Zipper Entry w/ Milwaukee Signature Hardware Smart Mask Climate Control Insole w/ Flex Power Toe Design Linings are Moisture Wicking, Anti-Fungal, Anti-Bacterial